From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57A59C2D0C0 for ; Mon, 23 Dec 2019 12:06:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1314B20715 for ; Mon, 23 Dec 2019 12:06:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="Q98VjP1I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726873AbfLWMGd (ORCPT ); Mon, 23 Dec 2019 07:06:33 -0500 Received: from mail.skyhub.de ([5.9.137.197]:58820 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbfLWMGc (ORCPT ); Mon, 23 Dec 2019 07:06:32 -0500 Received: from zn.tnic (p200300EC2F0ED6007C3BCB4901AE3123.dip0.t-ipconnect.de [IPv6:2003:ec:2f0e:d600:7c3b:cb49:1ae:3123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id A35131EC0391; Mon, 23 Dec 2019 13:06:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1577102790; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=Eujr/vAbQ2+cnbA/Y/6VFm+E4rkaCIhGe6e2vcZvass=; b=Q98VjP1I9b3remsMyKwJzpRUKaHZAGkbkSljIct6MbXJSaxbb/Zr2/0DAvMFaDOtdO0cJ2 8skqG+iJpT//VlShtc9qkPMGbl6+gkVrMILWj8nHb/Hg3OVvInUZoAy5St4UzTF3/TWey9 w84WUwbP9AWTpFtlXBLnJA4uSYQ0urk= Date: Mon, 23 Dec 2019 13:06:22 +0100 From: Borislav Petkov To: Andy Lutomirski Cc: John Andersen , Thomas Gleixner , Ingo Molnar , X86 ML , Paolo Bonzini , "H. Peter Anvin" , "Christopherson, Sean J" , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , LKML , kvm list Subject: Re: [RESEND RFC 2/2] X86: Use KVM CR pin MSRs Message-ID: <20191223120622.GC16710@zn.tnic> References: <20191220192701.23415-1-john.s.andersen@intel.com> <20191220192701.23415-3-john.s.andersen@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 22, 2019 at 11:39:19PM -0800, Andy Lutomirski wrote: > FWIW, I think that handling these details through Kconfig is the wrong > choice. Distribution kernels should enable this, and they're not > going to turn off kexec. Nope, the other way around is way likely. > Arguably kexec should be made to work -- there is no fundamental > reason that kexec should need to fiddle with CR0.WP, for example. But > a boot option could also work as a short-term option. The problem with short-term solutions is that they become immutable once people start using them. So it better be done right from the very beginning, before it gets exposed. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette